Prefabricated Reinforced Concrete House

The reinforcement of prefabricated concrete houses should be based on the actual safety assessment of the building. Not all situations are suitable for perimeter reinforcement, and targeted solutions should be selected according to specific issues.

1. Typical Scenarios Unsuitable for Perimeter Reinforcement

• Prefabricated Slab Buildings After Fire: Early prefabricated slabs often employed prestressed technology, with a steel reinforcement protective layer thickness of only 25 millimeters. When the fire temperature exceeds 650°C, the strength of the prestressed steel reinforcement is almost completely lost, leading to a sharp decline in structural load-bearing capacity. In such cases, perimeter reinforcement is not only costly but also difficult to guarantee safety, and direct demolition and reconstruction are usually recommended.
• Cracking Due to Foundation Settlement: The upper reinforcement in prefabricated slab buildings is relatively small, and foundation settlement can easily cause complete slab fractures at the supports. Perimeter reinforcement cannot address the root cause of settlement, and the reinforcement cost may approach that of reconstruction, making it extremely uneconomical.

2. Reinforcement Methods for Insufficient Local Load-Bearing Capacity

If a prefabricated slab building only has issues with local load-bearing capacity, the following mature techniques can be employed:

• Section Steel Reinforcement Method: Install section steel along the four corners beneath the prefabricated slab, transforming the original unidirectional load-bearing into octagonal support, significantly enhancing the floor's load-bearing capacity.
• Carbon Fiber Bonding Method: Strengthen the structural tensile properties using high-strength carbon fiber cloth, suitable for crack repair and load-bearing capacity reinforcement. For example, a prefabricated slab office building constructed in Shanghai in 1982 was successfully renovated into a high-end hotel through carbon fiber reinforcement, validating the technical feasibility.
• Plywood Reinforcement Method: Bond steel plates or composite materials to the surface of the prefabricated slab, forming a composite structure to improve overall stiffness.

3. Optimization Solutions for Non-Structural Issues

If the building poses no structural hazards but only suffers from poor living conditions (such as cracks, aging pipelines, and inadequate thermal insulation), priority can be given to applying for subsidies for old residential area renovations. Performance can be enhanced through the following measures:

• Crack Repair: Fill cracks with epoxy resin and other materials to prevent steel reinforcement corrosion.
• Pipeline Replacement: Update aging water and electricity pipelines to reduce safety hazards.
• Installation of Thermal Insulation Layers: Improve the building's thermal performance and enhance living comfort.
  Such solutions are far less costly than perimeter reinforcement and can systematically address non-structural defects.

Conclusion: The reinforcement of prefabricated concrete houses should be based on safety assessment results. For severe damage such as fire and settlement, priority should be given to demolition or reconstruction; for insufficient local load-bearing capacity, techniques like section steel and carbon fiber can be selected; for non-structural issues, optimization through renovation subsidies is recommended. Blind perimeter reinforcement may backfire, and scientific assessment is necessary before making decisions.